download cscope from http://sourceforge.net/projects/cscope/files/
$sudo apt-get install libncurses5-dev
$./configure --with-flex
$make
$sudo make install
downloadcscope_maps.vim from http://cscope.sourceforge.net/cscope_maps.vim
copycscope_maps.vim to ~/.vim/plugin/
$cscope -R
$cscope -R